A cellular wireless communication system adopts a cellular wireless networking mode, which connects terminals and network devices through wireless channels so that users can communicate with each other during movement. The cellular wireless communication system generally employs a common channel mechanism, which includes: achieving a spectrum synchronization and a time synchronization between a base station and a terminal during a power-on initializing stage through a pre-assigned common channel, so as to demodulate control data and service data; and after achieving the spectrum synchronization and the time synchronization, directly acquiring, by the terminal, important information related to system configuration, system management and link control from the pre-assigned common channel. Thus, the common channel is essential to the cellular wireless communication system.
In order to use the common channel mechanism in the prior art, the system is required to have fixed available spectrum as the carrier for the common channel. According to the existing fixed spectrum assignment mode, the spectrum of the common channel is fixed and known, and a common channel search and synchronization can be quickly and reliably performed between a base station and a terminal, and thus the availability and reliability of the common channel are ensured. However, the existing fixed spectrum assignment mode has a low efficiency and wastes spectrum resources. With the rapid increase of demands on mobile services, the utilization efficiency of the spectrum resources needs to be improved. The Dynamic Spectrum Access (DSA) technology employs an “opportunity type” access to the spectrum, which can solve the current problem of low utilization efficiency of the spectrum.
However, the DSA system adopts a dynamic spectrum assignment mode. The spectrum used by the system depends on current spectrum environment, and available spectrum is usually uncertain. Thus it is impossible to predetermine a fixed available spectrum as the carrier for the common channel in the fixed assignment mode. That is, the prior art does not provides a solution for using the common channel mechanism in the DSA system (i.e., the dynamic spectrum environment).